When a device, such as a telematics device or mobile telephone, is powered on, the processor of the device may need to execute a series of instructions to load the operating system of the device. To initiate the load, the processor will execute a boot sequence, which includes the initial set of instructions or operations that the processor performs when the device is powered on. The initial set of instructions or operations, however, must also be loaded onto the processor. Thus, the processor is typically programmed to automatically retrieve an initial data block containing a set of instructions or operations from a predetermined address in memory. The initial set of instructions or operations are referred to as a boot loader. In many devices the accessed memory is a NAND flash memory device.
One issue that arises with NAND flash, is that read inability errors are observed more often in NAND flash memory devices. Three causes of a read inability error are a bad block error, e.g. a block has been physically damaged, a data retention error, and a read disturb error. Of these, only a bad block cannot be cured by a memory refresh operation because the block error is a permanent error. Typically a boot loader includes instructions for handling a read inability error, including a bad block error, when loading the operating system of the device. When a read inability error occurs in the block containing the boot loader, however, the device is rendered inoperable because the boot loader cannot be loaded, and the sequence for loading the operating system from the flash memory device cannot be accurately performed. Thus, there is a need for a method and system to detect and handle a read inability error in the block containing the boot loader of a device.
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.